White deposits on spark plugs; water in fuel?

[2fast4mom]

I changed my spark plugs on the 280 today, and found that 4 of the plugs had varying amounts of a white, chalky, calcified substance on them:

Two ways at least that water can get in the fuel, bad gas from a marina pump, or bad cylinder head o-rings. I am thinking the odds of both sides o-rings failing at the same time are fairly astronomical, therefore the bad marina gas theory.

The last 2 times I filled up at Tower Park Marina, the boat idled very poorly upon re-start at the dock (almost died, acting loady), until I rev-ved the motor once, then it settled back down each time.

Also, during the same outing the same day, the boat began to "trailer-hitch" very sporadically, as if I was cutting through weeds (that's in fact what I thought it might have been, hitting spots of hydrilla) at midrange cruising speeds (4000 rpm or so). WOT did not seem to be affected.

I changed the filters too, obviously!

Tomorrow we go to the lake....I am hoping that we don't have the proverbial "Bad all-of-a-sudden" (daughter's euphemism) and will report back if all is well.

Have you guys seen this before on plugs?

 

[alli ss]

I have seen it. be sure to dump the seperator and change the inline filter. putting fuel in stirs the tank and by watching apollo13- stirring the tank is not good :shock: next time just go hang out in the marina and let it settle for a lil while :wink:

 

[2fast4mom]

Thanks Dusty,

Just got back from lake pulling knee boarders and skiers 3 hours today, ran flawlessly except for one "burp" at 2600 rpm one time only, other than that it was perfect.

 

[John Richied]

Sounds good Lou... how do the spark plugs look now? I would check the fuel filter too for water.
Maybe that’s the epoxy used to smooth the air intake??? Rut row, dat ain’t good.

next time just go hang out in the marina and let it settle for a lil while

In a boat doesn’t the fuel end up bouncing around mixed up all the time anyway???

 

[alli ss]

not in an 03 john- you're thinking of an 02 :lol:

 

[hack02]

That electrode is burning a pretty tan color isn't it.

 

[JR]

white deposits

Lou,
If ti were me I would either borescope those cylinders or remove the heads. That could be aluminum oxide fro the piston tops, it is usually shinier but it could have oxided.
It could be the difference between a piston change and a sleeve....
JR

 

[2fast4mom]

Thanks JR,

I don't think it is aluminium oxide and if it were, this motor would not be running like a scalded cat. The deposit residue was much lighter and "fluffier" than the picture allows. I thought about aluminium also but ruled it out after close examination and multiple local opinions, guys who saw the plugs firsthand.

I will pull the plugs and dump the fuel filter and see what she looks like now. A head pull certainly isn't ruled out, but what could cause aluminium meltdown when the EGT's and water temp have been monitored ceaselessly and the motor runs fine? The stereo EGT's have never gone above 1100, nor have I been stringing this motor out on recent trips.

In the 280, timing and other operational parameters are adjusted in realtime by the ECU. I would think that I would have gotten a horn or something else if the aluminium was melting down.

Re pulling the heads--all I might find is bad news, right? :lol: I am a big fan of denial.

Yea Hack, all the electrodes look nice and Hershey. Another indication that temps in the chambers are safe as houses.

 

[John Richied]

Pulling the heads you might find good news too… If everything looks fine install new head gaskets and call it good!

What compression are you running to what mix of race fuel?
The price of new head gaskets is pretty cheap compared to a new powerhead… but then you know that. :wink:

 

[froggy]

Lou,

Since you live in the land of fruits and nuts, you also have to run foo foo gasoline. You know, the botique kind specially blended for a single county to "eliminate" pollution. What you may be reading could be a product of 20%+ ethanol (oxygenate). Alcohol causes a motor to run lean due to its high oxygen value. A 20% blend might cause this white stuff and not be harmful. Watch out for a 30% blend though. You may have to check the specific gravity of the gas you are buying and if it indicates a high ethanol content, just use a DDT and change your fuel offset to +2 to +6% or more.

Our President has declared that botique blends will be unnecessary through the end of the year although I'm not sure that California has the ability to change that fast.

Hope this helps.

froggy

 

[Forkin' Crazy]

I would pull the heads too, just to be safe.

Are you sure those were aquatic weeds you were running over? If not I call that a surge and that means lean to me.

See if you can get some av gas to mix with your premium. I'd say about 20% or so.

 

[John Richied]

I think Lou all ready mixes 115 race fuel with 91 pump fuel...?

 

[2fast4mom]

Thanks Froggy, it was great to meet you at the Allison Expo and good to hear from you. Thanks for reminding me about those "boutique" blends.

And Forkin', thanks for your input as well. Yes, my standard practice, as John says, is to run 20% TT111 Conoco-Phillips race fuel (111 octane) splashed with 91 octane California premium. 5 gallons of race fuel to 20 gallons of premium in a 30 gallon tank.

BUT here's what happened, I seriously underestimated the distance to Sacramento and/or the boat's gas mileage. I was forced to buy gas at a strange gas dock offering no premium, only 89 octane. I babied the boat back to the trailer after filling up on that unknown stuff - probably contaminated slime.

Then I also filled up twice at Tower Park, they do have premium and I did mix the race fuel at those times. Still, this is a lesson for me, no more on-water gas!!

Anyway, heck with it, I'm pulling the heads and will post pictures. An ounce of prevention is worth $10,000 in cure, point well taken.

Now guys...WHAT do I need to know about removing and reinstalling O-ringed heads? Do I need to replace the o-rings and the large wraparound seals or should they be re-used? Thanks... :wink:

 

[alli ss]

they have to be replaced lou. everytime I pull mine out they expand and won't even go back in the slot :lol:

 

[2fast4mom]

Thanks Dusty. According to parts espresso it's like a $120 proposition....gotta love mama Merc's platinum-encrusted parts... :evil:

 

[GPI Racing]

If your careful you can reuse them. The o-rings expand because they react to the oils and such on our hands. (body oils) Most of the time the cylinder o-rings need to be changed anyhow as they have a tendency to burn on one side. The outside 'ring' can be reused and to get it to proper size put it in the freezer. The cold will shrink the rubber. I also cool the head to not heat up the rings when they are placed in the head. Coat the head with vaseline or another similar product to hold the rings and outside 'o-ring' in place. But if your careful and don't contaminate from the start, the parts will be of proper size for reinstallation.

Randy

 

[alli ss]

I take my heads off about 5 times a year. I never wanted to chance it (not getting them to fit) but never thought about reusing the outside one. does the vaseline not mess up the rubber being on it the whole time it's in the motor? and my cyl rings are always kinda flat and I have been skeered they might leak. what's the chance on that? when I take mine off I always need to put it together quick so I always have a set handy since I don't know where I'd even begin to find a set last minute :lol:

 

[John Richied]

I think Randy has done this a few times… pretty cool trick!
If you pull your heads off 5 times a year Rusty then I would think they would be in good enough shape to use the freezer trick on at least every other time???

Just curious why do you remove your heads five times a year?

 

[alli ss]

now I'm curious as to why you don't? :lol:

 

[Yellowallison]

now I'm curious as to why you don't?

.. cause PINKIE hasn't seen an article in B&W yet on how to do it YET :?: :?: